Regulators are directing US operators of Boeing Co. 777 widebody jets to repair aircraft to address concerns about potential fuel-tank explosions, according to a filing Monday.

A proposed airworthiness directive from the US Federal Aviation Administration calls for operators to inspect the jets and install Teflon sleeves and cap fasteners to certain parts of the center, left and right main fuel tanks, according to the filing. The order would apply to 282 aircraft, the FAA said.

The action follows a Boeing service bulletin issued in August and expands a similar FAA directive from 2017 to address a larger number of 777 models, from the -200 to popular -300ER series. It’s intended “to prevent arcing inside the main and center fuel tanks in the event of a fault current or lightning strike, which in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss of the airplane,” the filing said.

The FAA estimates it will take about 90 hours per plane to conduct the inspections and repairs at a total cost of $14 million for the US fleet of the twin-aisle jets. Airlines would have 60 days after the directive takes effect to adopt the new inspection program and as long as 60 months to make the repairs.

Boeing’s shares dipped less than 1% to $156.70 at 1:15 p.m. in New York. Through the close of Friday’s trading, the stock had declined 21% this year.

“We are aware of the FAA’s notice of proposed rulemaking and had previously issued guidance to 777 operators on this,” Boeing said via email. “We fully support the FAA’s recommendation to make that guidance mandatory.”